The present invention relates generally to stringed musical instruments and, more particularly, to an adjustment apparatus for adjusting the bridge or baseplate float angle of a floating tremolo mounted to a stringed musical instrument.
Strings of a musical instrument, such as a guitar, extend lengthwise along the neck and are supported above the neck between two contact points, typically between the nut located at the head of the instrument, and the saddle element of the bridge located at the base of the instrument. Each of the strings also typically extends beyond the contact points, including past the nut at the head end, where each string is secured to a tuning peg for adjusting the tension of the string, and past the saddle at the bridge end, where each string extends beyond the saddle contact point and is anchored to the instrument.
The sound produced by each of the strings is affected both by the string length (e.g., the length of the string between the two contact points) and by the tension of the string. On certain stringed instruments such as an electric guitar, string length is typically adjusted by adjusting the distance between the contact points at which the string contacts the saddles of the bridge and the nut. This is generally referred to as harmonic or string length tuning. The tension of the strings is also generally adjusted by adjusting the tuning pegs, or finer adjustments made at the bridge by some guitar tremolo systems, which serve to increase or decrease the tension of the strings. This adjustment is referred to as pitch or fine tuning of the strings. Typically, each one of the strings may be tuned (both harmonic and pitch) independently from the other strings of the musical instrument.
The action of the strings, or the height of the strings above the fretboard, is another parameter that can usually be adjusted to the desires of an individual player who may prefer that the stings sit closer to, or farther from, the fretboard for playability purposes. Bridges thus can be adjustable to hold the strings at a settable height above the fingerboard of the instrument.
Tremolo devices are used for significantly reducing or increasing the tension of all of the strings of the musical instrument simultaneously, thereby producing unusual tone variations or special sound effects. Although the effects achievable with tremolo devices on guitars and the like were popularized in the 1960's, early tremolo devices were not readily adopted because they frequently caused the strings to go out of tune. However, in the late 1970's and early 1980's, tremolos were embraced by both rock stars and casual players as a result of several inventions by Floyd Rose, the named inventor herein, because such Floyd Rose tremolos alleviated the problems associated with the strings being detuned during tremolo use.
In U.S. Pat. No. 4,171,661 (hereinafter “the '661 Patent”), Rose's original tremolo patent, the disclosure of which is incorporated by reference herein, the bridge of the musical instrument is provided on a floating tremolo device and the strings are held or “locked” at or in the vicinity of both the bridge and the nut of the instrument so as to be restrained against relative sliding movement during activation and return of the tremolo device. In this manner, after the tremolo is used and then returned to an inactive position, the strings return to the same tension as before activation and, therefore, remain in tune. The bridge also cantilevers or floats between an upwards and downward bending position during use of the tremolo system and should return to a steady-state position or float angle set for the desired string action.
A guitarist or guitar technician may, nevertheless, need to adjust the bridge float angle in a floating tremolo system. The bridge float angle can change over time based on play, wear, change of string gauge, loss of tremolo spring tension, and other factors. The bridge float angle is typically set to be parallel with a top surface of the guitar body.
In order to adjust the bridge float angle of the tremolo device such as is disclosed in the '661 Patent, the user must adjust the tension of the springs that hold the floating tremolo in its neutral position and allow the tremolo to change angles during use. To do so, the adjustor must first gain access to the springs, which are disposed within the guitar body and accessed through a cavity in the rear surface of the guitar body.
The tremolo springs are usually anchored to the guitar body via an anchoring plate that is fastened to the underside cavity by a pair of anchoring screws. This cavity is ordinarily covered by a protective cover plate that is fastened into rear surface of the guitar body by a number of cover plate screws. As a result, adjusting the bridge float angle can be time-consuming and difficult since it takes time and effort to remove all of the cover plate screws, make the bridge angle adjustment, and then replace the cover plate screws. Further, there are typically three or more tremolo springs attached to the anchoring plate and care must be exercised in adjusting each of the two anchoring screws so that the tension on all of the springs remains constant. Still further effort is required to make the adjustments from the bottom of the guitar, and then flip over the guitar to check the new float angle, and if not quite correct, the guitar must be flipped over again, adjusted, re-flipped over and checked again. This adjust, flip over, and re-adjust process can be time-consuming and frustrating.